Outcome evaluation of fruits and vegetables distribution interventions in schools: a systematic review and meta-analysis

Abstract

Objective: Fruits and vegetables (FV) distribution interventions have been implemented as a public health strategy to increase children's intake of FV at school settings. The purpose of this review was to examine whether snack-based FV distribution interventions can improve school-aged children's consumption of FV.

Design: Systematic review and meta-analysis of articles published in English, in a peer-reviewed journals, were identified by searching six databases up to August 2020. Standardised mean differences (SMD) and 95 % CI were calculated using a random effects model. Heterogeneity was quantified using I2 statistics.

Setting: Population-based studies of interventions where the main focus was the effectiveness of distributed FV as snacks to schoolchildren in North America, Europe and Pacific were included.

Results: Forty-seven studies, reporting on fifteen different interventions, were identified; ten studies were included in the meta-analysis. All interventions were effective in increasing children's consumption of FV, with only one intervention demonstrating a null effect. Pooled results under all classifications showed effectiveness in improving children's consumption of FV, particularly for multi-component interventions at post-intervention (SMD 0·20, 95 % CI 0·13, 0·27) and free distribution interventions at follow-up (SMD 0·19, 95 % CI 0·12, 0·27).

Conclusions: Findings suggest that FV distribution interventions provide a promising avenue by which children's consumption can be improved. Nonetheless, our results are based on a limited number of studies, and further studies should be performed to confirm these results. More consistent measurement protocols in terms of rigorous study methodologies, intervention duration and follow-up evaluation are needed to improve comparability across studies.

Keywords: Fruit; Meta-analysis; Schoolchildren; Snacks; Systematic review; Vegetable.

Fig. 1

Flow diagram of search strategy and review process based on PRISMA statement. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses

Fig. 2

Summary of study quality assessment using the Effective Public Health Practice Project (EPHPP) quality assessment tool for quantitative studies. Criteria Scale: 1 – strong, 2 – moderate, 3 – weak, N/A – not applicable. Global Rating System: 1 – strong (no weak ratings), 2 – moderate (one weak rating), 3 – weak (two or more weak ratings). QA Tool accessible through http://www.ephpp.ca/PDF/Quality%20Assessment%20Tool_2010_2.pdf

Fig. 3

School-based interventions to promote fruit and vegetable consumption. Meta-analysis of intervention sustainability at post-intervention and at follow-up. (Standardised mean differences and 95 % CI). ¹Measurement at post-intervention time point; ²measurement at follow-up time point

Fig. 4

School-based interventions to promote fruit and vegetable consumption. Meta-analysis of intervention approach (stand-alone or multi-component) at post-intervention and at follow-up. (Standardised mean differences and 95 % CI). ¹Measurement at post-intervention time point; ²measurement at follow-up time point

Fig. 5

School-based interventions to promote fruit and vegetable consumption. Meta-analysis of intervention type of distribution (free and subsidised) at post-intervention and at follow-up. (Standardised mean differences and 95 % CI). ¹Measurement at post-intervention time point; ²measurement at follow-up time point